Occurrence of selected aliphatic amines in source water of major cities in China.

The formation of toxic nitrogenous disinfection byproducts (N-DBPs), such as nitrosamines, halonitromethanes and haloacetonitriles, from reactions between chlorine/chloramine and dissolved organic nitrogen in drinking water has caused great concern with regarding public health. This study revealed the occurrence of 17 aliphatic amines, some of which have been confirmed to be the precursors of N-DBPs, in source water across China. A sensitive method based on benzenesulfonyl chloride derivatization and liquid-liquid extraction followed by GC-MS analysis was established for the simultaneous analysis of the selected amines in aqueous samples. In total, 37 source water samples from the capital cities of 20 provinces were collected for the survey. Among the 17 amines, 14 were detected with an average frequency of detection of 36%. The most relevant amines in terms of frequency and maximum concentrations detected were dimethylamine (100%, 24.82 microg/L), methylamine (78%, 0.92 microg/L), N-methylethylamine (70%, 8.84 microg/L), propylamine (59%, 10.69 microg/L), diethylamine (54%, 3.76 microg/L), N-methylbutylamine (35%, 3.07 microg/L), N-ethylpropylamine (35%, 0.52 microg/L), and piperidine (32%, 2.35 microg/L). This is the first large scale survey of the aliphatic amines occurrence in source water in the world. The wide presence of nitrosamine precursors like dimethylamine, N-methylethylamine and diethylamine, and the precursors of haloacetonitriles and halonitromethanes like methylamine and propylamine suggests that better source water management is required to ensure the safety of drinking water.